Steel alloy



. Patented New. 2%, 1927.

sent

new i. arms, or LATE-03E, rnnnsrtvanm, .assrenon are persons mnorarc STEEL COMPANY, OF LAYER-013E,

VAMA. V s'rnnn No Drawing.

The invention relates to that class of alloy steels, ordinarily known as stainless, which are resistant to attacks of such acids and other substances as are met with in the cus a ternary uses of the steels. As heretofore produced, such steels, whilehaving fairly good stainless properties when hardened and polished, have poor stainless properties in their unannealed soit state, and even when heat- 30 treated to bring out their best physical properties they are only fairly. strong and ductile.

The oh] ect ofzthe invention is to provide a steel alloy of this type which is highly resistant to attack in its annealed as well as in its hardened state, and which in its heattreated condition is very strong and ductile.

The alloy steel provided according to the invention contains from about .50 to .80% carbon and from about 16.00 "to 19.00%

chromium, the remainder being iron except for the usual amounts of other elements such .as sulphur, phosphorus, silicon and mangenese, which are ordinarily present as impurities or as incidental to manufacturlng E5 processes.

The sulphur and phosphorus should he as low as possible, while sillQQn and manganese may and chromium content the preferred steel alloy contains about ..60% carbon and about v 17.00% chromium. q

' As an example ofthe stainless property of the preferred analysis. ofthis steel in its annealed state, samples of it having a Brinell hardness of 17 0, when subjected to the stand Application filed April 2,

be present to the extent of about of each, as in most steels Within this relatively small range of carbon .PENNSYL'VANIA, A CORPORATION OF PENNSYIJ- annoy.

1926. serial no. eases.

grams of copper, and when subjected to the standard nitric acid and acetic acid tests they showed a removal "oitno metal.

As to the physical properties of the preierred analysis of this steel alloy, annealed samples having a Brinell hardness of 187 showed an average elastic limit of 74540 lbs.

per square inch, a tensile strengthof 101180 lbs. per squareinch, an elongation of 23% in two inches, and a reduction ofarea of.

54.3%. In a semi-annealed state, having a Brinell hardness of 217, samples or the same steel alloy showed an average elastic hm1t of 84080 lbs. per square inch, a tensile strength of 106530 lbs. per square inch, an'

elongation of 22% in two inches, and a reduction of area of 50.4%. In a heat-treated,

hardened state, having a Brinell hardness of 269, samples of the same steel showed an vas average elastic limit of 1217 7 0 lbs. per square inch, a. tensile strength of 134500 lbs. per square inch, an elongation of 13% in two inches, and a; reduction of area of 39.8%.

From the-foregoing it abundantly appears that the improved stainless steel alloy is highly resistant to attack in its annealed as ell as in its hardened state, and that it has ength and ductility. These profit eItIe5,-.b and physical, are mug super or to those'ofany known stainless steel 1 retains a better cutting edge, and is purities and as incidental to manufacturing processes,

ened state.

I the alloy being h y. resistant-t atta'ck in'its annealed as well'as in its hard: so

7 In testimony whereof,-'I. i n m I 7 'DA-VID :JJGIIIES' 

